Septal puncture through an intact atrial septum from the right atrium to the left atrium is often necessary. This is traditionally performed using rigid, long needles, such as Brockenbrough or Ross needles. In all types of septal puncture, the needle that is used to puncture the atrial septum poses a high risk of inadvertent puncture through tissue other than the septum primum, for example, the atrial free wall, posing a significant risk to the patient. For patent foramen ovale (PFO) closure, this risk is potentially even higher, due to the fact that the septal tissue is defective and often thinning, and may stretch an even greater amount during the puncture procedure, bringing the tip of the needle dangerously close to the atrial free wall or the left atrial appendage.
The currently offered SafeSept® Transseptal Guidewire by Pressure Products Medical Supplies Inc. provides a sharp but atraumatic curved guidewire that is fed through a sharp transseptal needle disposed within an introducer. The introducer includes an outer sheath and a tapered dilator which telescopes out of the sheath. The transseptal needle in turn is disposed into the dilator. The tapered dilator is used to tent the septum without the needle extending beyond the distal tip of the tapered dilator, the sharp guidewire is advanced out of the dilator to penetrate the septum as its column is supported by the needle. Because of the columnar support, the guidewire is able to penetrate the septum without bending or buckling the otherwise flexible guidewire. Without such columnar support, the guidewire would not have the columnar strength to be pushed through the septum. Once the guidewire has penetrated the septum, the sharp needle is advanced out of the dilator over the guidewire through the septum into the left atrium. The dilator is advanced over the needle, then the sheath is advanced over the dilator into the left atrium. With the sheath safely in place, the tapered dilator, needle, and guidewire are removed so that a catheter or other cardiac instrument may be introduced into the left atrium through the sheath.
In the SafeSept® Transseptal Guidewire Needle Free produced by Pressure Products the method of septal penetration is the same as with the SafeSept® Transseptal Guidewire, but no transseptal needle is provided. Only the atraumatic sharp guidewire is used to penetrate the septum and the tapered dilator is advanced over the guidewire into the left atrium. Because no needle is employed, it is possible that both the tapered dilator and sheath may be able to be advanced through the septum by the use of an oscillating rotation of the tapered dilator and/or sheath as it is being advanced.